From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.0 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 31E2BC43387 for ; Fri, 18 Jan 2019 13:44:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 026D02086D for ; Fri, 18 Jan 2019 13:44:32 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=baylibre-com.20150623.gappssmtp.com header.i=@baylibre-com.20150623.gappssmtp.com header.b="UrHguNnD" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728015AbfARNoa (ORCPT ); Fri, 18 Jan 2019 08:44:30 -0500 Received: from mail-wm1-f67.google.com ([209.85.128.67]:55918 "EHLO mail-wm1-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727707AbfARNo2 (ORCPT ); Fri, 18 Jan 2019 08:44:28 -0500 Received: by mail-wm1-f67.google.com with SMTP id y139so4510908wmc.5 for ; Fri, 18 Jan 2019 05:44:27 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=baylibre-com.20150623.gappssmtp.com; s=20150623; h=from:to:cc:subject:date:message-id; bh=6xhP3iFZu+KY4p6uA7nxYzqv59edNtjKSfjSMfB8u+8=; b=UrHguNnD28eUc06ATqkWwzWIuediGZIT8Dojl9XpKM6si+KEAo2f5PlG2pg95exakT MLQxBCSC0qc93Qq2SzWaa+AwWlvX/zyeoXg1MayvY31RwVgkoOtordjOHMGHlSVZLPMg S+KEoJ3I563xPNO/nG1AY7RFJKNM/VFPv1RIVXB7XTxWormA7mXAKRE377Hu+7b8ND0G x+cdGEukxB69l9/3f2p86X01VUTaygkoyEsimE8CxVnUK2xV0N9EDoFujiLjJslz+/2m djYhUUeDzLr4GTVaaFvF/pA6/hlj3MOTyhBmUnSpeZYF6POoYJXZ5vffMub2r9C0QT6Z HMBg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id; bh=6xhP3iFZu+KY4p6uA7nxYzqv59edNtjKSfjSMfB8u+8=; b=kjUXHq3ejUXosQtSAGI5e4LCjAednD2v5ftAqmEOmNmYHIlbaVh3WUpHwpX+sQiofj qLqqp/Ka9uwvmcEMLzjN2JqAL+LwA/50ycgoORhc3QTJPzpFUCZcsjxNYE0y+L1OHQo5 hL+8KdEE7ZIkN43LV10Zdeb7AIl2qA6uI6PeITXYCuowdhpWCjEEixz68gRk0Q+Zi2tx EUOpCBqdY1nDleggN9Y5l3RqvupLRN8x/mAfs1hLW86rgthhUmQKfSseZ7Zm7d1XVccc Xfyhnr37y300CPjBVlumAp0WpzO1XAIjhTrsSuDoz4Uj1Us/BGSL0O4TlCoZqlN2KfMv GB1w== X-Gm-Message-State: AJcUukf0Cx04UUBrb0eLkKiOQ0MvhijMLfZKKefBpWZe+S7YCaH49NNQ lcrfaaoWEesE/FCp9RSnll9ypg== X-Google-Smtp-Source: ALg8bN6q8pkGJRQqKhQVSRwKN5gJFmOp6G9FcYQc3pwLEAsOrr31MF/rkKFXCJD++LEhcH5RIccvsg== X-Received: by 2002:a1c:3d44:: with SMTP id k65mr15541959wma.76.1547819066534; Fri, 18 Jan 2019 05:44:26 -0800 (PST) Received: from localhost.localdomain ([51.15.160.169]) by smtp.googlemail.com with ESMTPSA id y13sm65912208wrn.73.2019.01.18.05.44.25 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Fri, 18 Jan 2019 05:44:25 -0800 (PST) From: Corentin Labbe To: corbet@lwn.net, hch@lst.de, m.szyprowski@samsung.com, robin.murphy@arm.com Cc: iommu@lists.linux-foundation.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, Corentin Labbe Subject: [PATCH v2] dma-debug: add dumping facility via debugfs Date: Fri, 18 Jan 2019 13:44:18 +0000 Message-Id: <1547819058-3552-1-git-send-email-clabbe@baylibre.com> X-Mailer: git-send-email 2.7.4 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org While debugging a DMA mapping leak, I needed to access debug_dma_dump_mappings() but easily from user space. This patch adds a /sys/kernel/debug/dma-api/dump file which contain all current DMA mapping. Signed-off-by: Corentin Labbe --- Changes since v1: - Use DEFINE_SHOW_ATTRIBUTE - Add Documentation Documentation/DMA-API.txt | 3 +++ kernel/dma/debug.c | 36 ++++++++++++++++++++++++++++++++++++ 2 files changed, 39 insertions(+) diff --git a/Documentation/DMA-API.txt b/Documentation/DMA-API.txt index e133ccd60228..78114ee63057 100644 --- a/Documentation/DMA-API.txt +++ b/Documentation/DMA-API.txt @@ -696,6 +696,9 @@ dma-api/disabled This read-only file contains the character 'Y' happen when it runs out of memory or if it was disabled at boot time +dma-api/dump This read-only file contains current DMA + mappings. + dma-api/error_count This file is read-only and shows the total numbers of errors found. diff --git a/kernel/dma/debug.c b/kernel/dma/debug.c index 23cf5361bcf1..b4827b1c9070 100644 --- a/kernel/dma/debug.c +++ b/kernel/dma/debug.c @@ -144,6 +144,7 @@ static struct dentry *num_free_entries_dent __read_mostly; static struct dentry *min_free_entries_dent __read_mostly; static struct dentry *nr_total_entries_dent __read_mostly; static struct dentry *filter_dent __read_mostly; +static struct dentry *dump_dent __read_mostly; /* per-driver filter related state */ @@ -840,6 +841,36 @@ static const struct file_operations filter_fops = { .llseek = default_llseek, }; +static int dump_show(struct seq_file *seq, void *v) +{ + int idx; + + for (idx = 0; idx < HASH_SIZE; idx++) { + struct hash_bucket *bucket = &dma_entry_hash[idx]; + struct dma_debug_entry *entry; + unsigned long flags; + + spin_lock_irqsave(&bucket->lock, flags); + + list_for_each_entry(entry, &bucket->list, list) { + seq_printf(seq, + "%s %s %s idx %d P=%llx N=%lx D=%llx L=%llx %s %s\n", + dev_name(entry->dev), + dev_driver_string(entry->dev), + type2name[entry->type], idx, + phys_addr(entry), entry->pfn, + entry->dev_addr, entry->size, + dir2name[entry->direction], + maperr2str[entry->map_err_type]); + } + + spin_unlock_irqrestore(&bucket->lock, flags); + } + return 0; +} + +DEFINE_SHOW_ATTRIBUTE(dump); + static int dma_debug_fs_init(void) { dma_debug_dent = debugfs_create_dir("dma-api", NULL); @@ -894,6 +925,11 @@ static int dma_debug_fs_init(void) if (!filter_dent) goto out_err; + dump_dent = debugfs_create_file("dump", 0444, + dma_debug_dent, NULL, &dump_fops); + if (!dump_dent) + goto out_err; + return 0; out_err: -- 2.19.2